Avalanche Safety

On one of my recent snowshoe outings, there was a sign near the trailhead warning that unexploded ordnance used for avalanche control may be in the area. The mention of possible explosives didn’t bother me as much as the grisly thought of being buried alive in the snow.  I never used to worry much about avalanches, but it seems snowshoeing is going to take me into places and conditions in the backcountry that I haven’t been or seen before. With the snow starting to pile up in the mountains, and me not knowing much about avalanches other than they’re very powerful and you don’t want to be in the path of one, I thought I should become more educated before my next trip out.

Snowshoeing at Carson Pass
Windblown Snow – Is this safe?

One statistic that immediately got my attention is that 90% of avalanche victims die in slides triggered by themselves or a member of their group. It’s not simply a matter of being in the wrong place at the wrong time. Thankfully, your best defense is not learning how to survive an avalanche; it’s how to avoid being caught in one in the first place. By doing some research and making observations while you’re out in the backcountry, you can eliminate and/or minimize your exposure to avalanche terrain.  It’s also good to bring along others when traveling in avalanche areas, as you may need someone to dig you out. When traveling with others, spread out and try to not expose the whole group to the same threat at once.

Slope Evaluation

Avalanches are possible on any slope that is steeper then 30 degrees. They occur most
often on slopes ranging from 35 to 50 degrees. Knowing this, you can possibly plan a route that keeps you away from any avalanche danger. Some compasses, such as the Suunto MC-2 Pro have a built in clinometer to measure a slope. If you are traveling on a slope less than 30 degrees, don’t forget to look uphill to make sure there is not a much steeper slope directly above you.

Inclinometer
Clinometer measuring 40 degrees on the Suunto MC-2 compass

Avalanche Red Flags

There is still a good chance you’ll be venturing in to areas with slopes greater than 30 degrees. In this case, it’s really important to keep any eye out for avalanche red flags. These are events and conditions that can increase avalanche risk:

  • Recent Avalanches: Check with local experts before you go to an area for any known recent activity.  A good place to start is avalanche.org.
  • Warning Signs: Look for cracking or collapsing snowpack. Listen for a “whumpfing” or hollow sound.
  • Recent Rain and Snow: Significant snowfall or rain during the past 24 hours can make snowpack unstable.
  • Windblown Snow: Windblown snow can load the leeward side (the side out of the wind) of a mountain even when its not snowing.
  • Rising Temperatures: Warm temperatures and gravity can cause the snow to creep downhill and become less stable.
  • Weak Layers: Unstable layers buried in the snowpack may give way even weeks after a storm or when no other Red Flags are present.   These layers may be difficult to identify though without some training and snow excavation.

More Resources

I’ve really only touched on the subject of avalanche safety here in this post, but hopefully it’s enough to make you more aware and get you started. Here are some of the great resources I found when researching this subject. On these sites you will find current avalanche conditions, safety tutorials, and plenty of other great information that could save your life!

avalanche.org: http://avalanche.org/
Avalanche Safety Tutorial: http://avalanche.org/tutorial/tutorial.html
Sierra Avalanche Center: http://www.sierraavalanchecenter.org/
Forest Service Avalanche Awareness: http://www.fsavalanche.org/

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